The present invention relates to a liquid crystal display device and more particularly to a liquid crystal display device with a reduced picture-frame area around the display area that does not contribute to the display.
To meet the growing demands for acquiring necessary information and performing computation anytime and anywhere, portable information processing devices as shown in FIG. 52 have been developed. The portable information processing devices include notebook type personal computers (hereinafter referred to as a notebook computer), word processors, a portable information terminal, and a pocket type computer.
These portable information processing devices mostly use a liquid crystal display device due to its small thickness, lightness, and small power consumption.
The liquid crystal display device comprises a liquid crystal display panel for displaying an image and a drive circuit. The drive circuit is provided around the liquid crystal display panel and constitutes a non-display area (so-called picture-frame area) that does not contribute to the display.
There have been growing demands in recent years for increasing the display area in the portable information processing devices so that the display can be viewed easily. A simple way of increasing the display area is to use a large liquid crystal display device but this degrades the portability, the very feature of the portable information processing devices.
Hence, certain picture-frame reduction techniques have been employed to reduce the non-display area and thereby increase the display area as compared with that of liquid crystal display devices with the same external size.
Such picture-frame reduction techniques are disclosed in Japanese Patent Application No. 75019/1994 and 297234/1995 and have been successful to some extent.
The inventors of this invention, however, have found that problems still remain to be solved in making the display area larger and the picture-frame area smaller than those of the conventional devices.
FIG. 53A shows a case ML of the liquid crystal display device mounted with a backlight comprising a light guide plate GLB and a fluorescent tube LP. FIG. 53B is a cross section taken along the line B--B of FIG. 53A. FIG. 53C is a cross section taken along the line C--C of FIG. 53A.
The conventional liquid crystal display devices, as shown in FIG. 53B and FIG. 53C, use lamp cables LPC1, LPC2 with round cross sections for supplying a voltage to the fluorescent tube LP.
Hence, the area where the lamp cables LPC1, LPC2 are installed in the liquid crystal display device becomes large, making it impossible to reduce the picture-frame area of the liquid crystal display device.